This invention relates to batteries. In the past, batteries utilizing intercalation compounds of graphite and fluorine as the cathode-active material and lithium metal as the anode have been found to be useful as primary batteries, e.g., see U.S. Pat. No. 3,514,337. However, such batteries, although of relatively high energy density, suffer serious deficiencies in that they are primary batteries, i.e. they are not capable of being recharged. In contrast thereto, the present invention provides for batteries which in many cases have not only high energy densities but are also capable of being discharged and recharged over many cycles.
It is also well known (U.S. Pat. No. 3,711,334) to utilize molybdates (e.g. MoO.sub.4) rather than the layered chalcogenides (e.g. TiS.sub.2) employed in the instant invention. In this prior art reference, the cell is not rechargeable and the lithium of the anode is converted to lithium oxide during discharge. In the instant invention, the lithium ions intercalate into the chalcogenide and upon recharging are readily redeposited on the anode in the form of lithium metal.
Broadhead et al (U.S. Pat. No. 3,791,867) makes use of an intercalatable transition metal chalcogenide and a material such as lithium. However, this patent utilizes iodine, bromine, sulfur, selenium or tellurium as the cathode-active material and the transition metal chalcogenide merely serves as the host structure for the cathode-active material.